Investigation of contemporary gilded forgeries of ancient coins

Four contemporary forgeries of ancient gold coins were investigated regarding techniques used for gilding, and the composition of the gold cover and the base metal core. The forged coins are a Daric of the Persian Empire, a Gold Stater in the name of Alexander, and two Solidi of the late Roman Empire. A combination of modern analytical methods such as Scanning Electron Microscopy (SEM), Electron Probe Micro Analysis (EPMA), X-Ray Fluorescence Spectrometry (XRF), and SecondaryIon Mass Spectrometry (SIMS) was used. The results demonstrate that the coins represent the main three technologies of gilding used in antiquity. The core of the Daric is a silver Siglos, plated by leaf gilding. The Gold Stater was forged by foil gilding using a silver core. The Roman Solidi have a core of either silver or copper and were plated by fire gilding. On account of our results it is possible to compare the forgers' profits made by use of the different technologies of forging.